Remote access to computer equipment is a rapidly developing trend. It is well known to access computer equipment over a dial-up connection using modems. It is becoming increasingly common to provide remote access via virtual private networks (“VPNs”), directly over digital subscriber line (DSL), cable and other types of high-speed internet links. Remote access can be used for a variety of useful purposes, such as enabling remote maintenance of computer equipment, without the problems associated with dispatching a maintenance person to the site of the computer equipment.
However, enabling remote access to computer equipment renders such equipment vulnerable to attacks from unauthorized persons who accidentally, or illegally, obtain the dial-up address of the computer equipment, and the passwords and other authentication information associated therewith.
The telecommunications industry is an industry with an interest in providing remote access to computer equipment resident at telephone exchange switches and used to operate the telephone exchange. However, the security vulnerabilities of prior art remote access methods has curtailed the development and deployment of remote access for telephone exchange switches.
One proposed means of providing remote access is described in U.S. Pat. No. 5,724,426 to Rosenow et al., which issued on Mar. 3, 1998. Rosenow discloses means for controlling access to computerized system resources to enable each new session to employ different encryption keys derived from multiple random numbers and multiple hidden algorithms without transmitting the keys across a communication line. Although Rosenow has merit, it is not entirely ideal for telephone exchange switches, because Rosenow relies on a central access control system that employs a dedicated parallel control network, such as a local area network (“LAN”), to centrally manage access control tables of an access-controlled system of resources.
Another proposed means for providing remote access is described in U.S. patent application Publication No. US2002/0095573 to O'Brien and published on Jul. 18, 2002. O'Brien describes an apparatus in which a secure access transceiver (i.e. modem) is provided for enforcing authenticated remote access to command controllable computer equipment. The secure access transceiver authenticates an entity seeking access to the computer equipment from a remote service point upon detection of a carrier signal during an initial handshake sequence. A data port on the secure access transceiver used to deliver data to the command controllable computer equipment is enabled only on authentication of the entity seeking access to the computer equipment and the data port is kept disabled otherwise, preventing data transfer through the secure access transceiver unless an authenticated connection is established. Although this system also has its place in certain applications, it does not provide an optimal solution for the need to enforce control over access to command controllable computer equipment because after a data port is enabled, and if protective measures have not been taken, the equipment is still vulnerable to attacks. Thus, an unauthorized user will have remote access to the command controllable computer equipment. In general, O'Brien assumes that the network providing the connection cannot be tampered with during the duration of the transaction after the initial authentication process.
Overall, the above-mentioned prior art to provide remote access to computer equipment is not suitable for certain applications.